| ??? 03/30/05 16:22 Read: times |
#90697 - I read the Datasheet of MID400 Responding to: ???'s previous message |
Erik Malund said:
I'd use a small transformer simply because its pins put the 220V further away from the low voltage circuitry than an optoisolator does. Maybe not a valid point, but I have seen too many sparks between probes and opto pins (and sometimes the probe has shorted 220V to 5V circuitry BOOM). The very fact that optoisos still come in DIL to separate the pins makes my case.
Again no "electronic" reason, just a better feeling. Erik Erik, I just went through the datasheets of the MID400 (the one Sasha proposed to 'spy' the 220V) and I see that this device is specially (and solely?) developed for 'AC mains control'. I quote the introduction of the datasheet: {} The MID400 is an optically isolated AC line-to-logic interface device. It is packaged in an 8-lead plastic DIP. The AC line voltage is monitored by two back-to-back GaAs LED diodes in series with an external resistor. A high gain detector circuit senses the LED current and drives the output gate to a logic low condition. The MID400 has been designed solely for the use as an AC line monitor. It is recommended for use in any AC-to-DC control application where excellent optical isolation, solid state reliability, TTL compatibility, small size, low power, and low frequency operations are required. {} Knowing this, does that still gives you a bad feeling about the device? If I may be so free, can I maybe ask you to have a quick scan through the datasheet of this device? Here's the link: http://www.fairchildsemi.com/ds/MI/MID400.pdf Would like to know your opinion. Best rgds, --Geert |
